1. Age- and site-associated biomechanical weakening of human articular cartilage of the femoral condyle 
M.M. Temple, Ph.D., W.C. Bae, Ph.D., M.Q. Chen, M.S., M. Lotz, M.D., D. Amiel, Ph.D., R.D. Coutts, M.D., R.L. Sah, M.D., Sc.D. 
Osteoarthritis and Cartilage 
Volume 15, Issue 9, Pages (September 2007)
DOI: /j.joca
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

2. Fig. 1
Structural and surface properties of human articular cartilage from the LFC and MFC. Cartilage thickness (A), reflectance score assessed after India ink staining (B), the variance of reflectance score (C), overall histopathological index of cartilage degeneration (D), and surface irregularity assessed by histopathological grading (E) from donors of Young (21–39 yrs old), Middle (40–59 yrs old), and Old (≥60 yrs old) age groups. n=8–12. *P<0.05, **P<0.005 vs Young age samples.
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

3. Fig. 2
Tensile biomechanical properties of samples described in Fig. 1. For specimens from the superficial, middle, and deep layers, the tensile equilibrium modulus (A), tensile ramp modulus (B), tensile strength (C), and failure strain (D) were determined from equilibrium and then non-equilibrium failure testing of articular cartilage from Young (Y), Middle (M), and Old (O) age donors. n=9–12. *P<0.05, **P<0.005 vs Young age samples.
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

4. Fig. 3
Biochemical properties of human articular cartilage samples described in Fig. 1. Cartilage tissue adjacent to the mechanical test specimens was analyzed for water content (A), DNA and calculated cell number (B), COL (C), COL in αCT (D), the fluorescence ratio (E) of pentosidine-associated fluorescence (Ex 335/Em 385nm) to pyridinoline-associated fluorescence (Ex 295/Em 395nm) and GAG (F). DNA, COL, and GAG were each normalized to wet weight. n=9–12. *P<0.05, **P<0.005 vs Young age samples. ††P<0.005 vs Middle age samples.
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions

5. Fig. 4
Summary of cartilage changes at early, intermediate, and late stages of age-associated degeneration in particular zones. Changes in superficial tangential zone (STZ), middle zone (MZ), and deep zone (DZ) are noted by ●, with parentheses signifying variable changes. Depicted are changes in mechanical integrity (degree of gray shading), articular surface wear, alterations of chondrocyte density, increase in intrinsic fluorescence, and loss of GAG (▨).
Osteoarthritis and Cartilage  , DOI: ( /j.joca )
Copyright © 2007 Osteoarthritis Research Society International Terms and Conditions